Consider defining a pattern rule, such as
As far as I understand Mathematica syntax, this rule means
whenever myFun appears with a single argument, replace the whole thing by the argument
Now, after the above definition, if we evaluate
we see that even though the pattern
x__ clearly symbolizes more than one argument, the single argument rule still gets executed!
Is this intended behavior? Maybe my syntax use is improper? How should I specify a single argument pattern rule which does not register with more-than-one argument patterns?